Based on the Stokes, the changes of the polarized light transmission characteristics were studied after the lasers of different incident polarizations transmit through the different concentrations of oil mist by measuring the degree of polarization respectively. Experiments were used the horizontal, 45°,90°,－45°linear polarized lights with the wavelength of 671 nm and 532 nm to make them incident on the five kinds of different concentrations of oil mist media respectively, and computed the degree of polarization of four polarized polarization state .The results show that, at the same mist concentration and the lasers with different wavelengths, the longer wavelength, the higher the degree of polarization. But the trend of each wavelength polarization curve with the concentration is the same. Under the condition of the same wavelength and with the changing of the mist concentration, the variation of the polarization degree of the horizontal and vertical linear polarized lights is bigger which is up to 50%, the variation of the polarization degree of the 135°and 45°linear polarized lights is lesser which is about 20%.